Clinical, electrocardiographic and myocardial biopsy studies were made in patients with Chagas' disease in an effort to correlate the results with the presence and titer of serum antibodies to laminin. No clear correlation was found between the antibody titers to laminin and the severity of clinical alterations or laboratory findings. Thus, it did not prove feasible to assign a pathogenetic role to antilaminin antibodies in Chagas' disease.